Change [1] started to implement new API with RevisionApi.review.
This change implements the following API methods:
* abandon
* rebase
* restore
* revert
* submit
* delete (draft)
SSH review command was migrated to utilize the new API.
Acceptance tests were added for the new API methods.
[1] https://gerrit-review.googlesource.com/48664
Change-Id: I2240759ba64401d0760c72490b9f4d05f965ecfc